【摘要】 介绍青岛胶州湾海底隧道的工程概况和邻近隧道爆破控制的研究现状。由位于断层破碎带f3-1中的典型断面ZK5+607的几何参数和地质资料构建三维尺寸为215m×86.1m×60m的数值计算模型,对后行隧道上台阶掏槽眼的爆破效应进行分析。采用国际上常用的计算模式模拟爆破荷载,根据FLAC3D动态计算的特点,将爆破荷载以等效应力的方式加载于模拟炮孔之上。以控制点振速峰值和塑性区体积为标准对施工方案进行优选,分析认为施工中应尽量减小各掌子面纵向间距、严格控制掘进进尺和装药不耦合系数、施作中空孔。用优选的方案进行研究并得出结论:爆破施工对海底隧道岩石覆盖层的影响范围在15m之内;施工洞和服务洞的围岩振动影响较大,且爆破工作面前方的爆破振动强度大于后方,在其影响范围内应注意加强监控量测并推迟二次衬砌的施作;施工洞拱部、先行洞迎爆面边墙是爆破振速峰值最大的部位,施工洞拱部出现了应力集中现象和拉应力区,施工中应加强支护。更多还原

【Abstract】 The subsea tunnel project at Jiaozhou bay in Qingdao and a study of blasting control for the twin tunnels are introduced.The section ZK5+607 located in the fault f3-1 is chosen as typical cross section,and a three dimensional numerical model(215m×86.1m×60m) is formed according to the geometric parameters and geological data of this section.The effect of blasting of cut holes in the upper bench of the tunnel excavated later than others is studied.An internationally commonly used calculation method is employed to simulate the explosion load,which is then imposed on the simulation blast holes in equivalent stress form,based on the characteristics of dynamic calculation of FLAC3D.Various construction schemes are compared by using the vibration velocity peak values of representative key points and plastic zone volumes.Suggestions are presented,such as minimizing the spaces between working faces,controlling the lengths of driving cycles and coefficients of decoupling charge,and using hollow holes.Further study is performed for the optimal construction scheme and the following conclusions are obtained.The scope of influence on rock overburden under explosion load is within 15m.Vibration responses of the main tunnel and service tunnel are obvious,and the blasting vibration intensity of the ahead-of-working-face surrounding rock is stronger than that of behind-working-face surrounding rock.Within the influence zone,monitoring should be strengthened and concrete lining should be delayed as much as possible.Peak values of vibration velocity occur on the excavating tunnel arch and wall facing the blasting side of the constructed tunnels,while stress concentrations and tensile stresses appear at the arch of the excavating tunnel.更多还原